Homes, offices, multiple dwelling units (MDUs), and other buildings are wired with coaxial cable and category 5 (CAT5) wire for video and data communications. A building may have more than one wiring system using coaxial cable, for example when service is obtained from a local cable TV provider and a direct broadcast satellite (DBS or SAT) provider. Cable TV signals distributed over coax are analog TV channels at 6 MHz spacing along with digital TV channels using specific 6 MHz bands. The frequency band used by a typical cable or community aerial TV (CATV) system is 5 to 860 MHz, including 5 to 55 MHz used for a reverse channel with cable modems. The coax wiring for a DBS system routes an L band signal comprised of several transponder signals, typically in the range of 950 to 1450 MHz, from an outdoor antenna and low noise block converter (LNB) into the building to integrated receiver/decoders (IRD). The IRD demodulates and decodes the digitally broadcast video signals and then outputs the signal to a TV monitor either at RF channel 3 or 4, or as composite or component analog video.
Category 5 twisted pair (CAT5) wiring is commonly used for data networking between computers, printers, and modems. CAT5 wiring may be wired in the building to wall outlets or user installed cable connecting between devices directly. A network hub or switch provides a physical junction between cables connecting to devices. These networks generally comply with IEEE-802.3, commonly referred to as Ethernet local area network (LAN). Ethernet also operates on coaxial cable. Fiber optic cable, IEEE-1394, and Universal Serial Bus (USB) each specify a wire and cable standard for interconnecting compatible devices.
Some buildings are wired with two sets of coaxial cable routed to each room. The use of each set of cable is determined by the user. One may be used for CATV and the other for SAT.
Customer premise equipment (CPE) such as IRDs and STBs connect to one of these wiring systems to receive or communicate signals. The systems operate independent of each other.